The French midfielder and the coach had a turbulent relationship when they worked together at Old Trafford and Pogba was frustrated by the way the Portuguese manager would cast players aside.
Opening up on the differences between Mourinho and his successor Ole Gunnar Solskjaer, Pogba told Sky Sports: "What I have now with Ole is different, he wouldn't go against the players.
"He wouldn't go against the players. Maybe Ole wouldn't pick them, but it's not like he puts them on the side like they don't exist anymore. That's the difference between Mourinho and Ole.
"Once I had a great relationship with Mourinho, everybody saw that, and the next day you don't know what happened. That's the strange thing I had with Mourinho and I cannot explain to you because even I don't know. So, yeah."
Pogba also suggested that the improvement in the performances of team-mate Luke Shaw are as a result of his relationship with Solskjaer, with the full-back having struggled to perform under Mourinho.
He explained: "Maybe [Solskjaer's methods work] because he is a bit closer to the people.
"Every coach has their own way to coach and deal with players, and as a player you have to adapt. Sometimes it doesn't suit you and sometimes it does.
"Ole has helped Luke a lot, it was a difficult season with Luke and Mourinho, and he has proved he has the quality he always had and the trust of the manager."